As in the case of the small tube writing implement described, for example, in DE-OS 30 23 189, in the case of this implement, liquid ink, via a small tube, is applied to the writing pad. In the small tube, a wire shaped or wick shaped writing element is arranged that, together with the interior wall of the small tube, forms ink feeding ducts. Said writing wick projects over the end of the small tube located on the outside and, together with it, forms the writing point. It can be slid axially in the small tube against the effect of a spring element. The spring element has the effect that the writing point in any writing postion remains in contact with the writing pad. By means of the axial movement of the writing wick that occurs automatically during the writing, impurities are removed from the small tube. In addition, the pump effect that occurs when the writing point is placed on the pad supports this effect.
In the case of the writing implement according to DE-OS 30 23 189, this spring element consists of an ink permeable plastic-foam cushion or similar device.
This plastic-foam cushion has two disadvantages.
On the one hand, the restoring force of the cushion decreases in the course of the usage period, whereby the operatability of the writing implement may be impaired.
On the other hand, a plastic-foam cushion of the density that is required for the purpose of elasticity has only a limited ink permeability.
In order to achieve, in the case of writing implements of this type, a better capacity for open storage than in the case of the known small-tube writing implements, unpigmented inks must be used instead of pigmented inks. It is known that the latter have a much better covering capacity than unpigmented ink types. In order to nevertheless achieve by means of these ink types a comparable blackening and covering capacity of the produced lines, a more intensive ink delivery is required. However, this more intensive ink delivery, in the case of the writing implement disclosed in DE-OS 30 23 189, is not ensured, mainly as a result of the plastic-foam cushion.